ASNer MoonlitShadow, who was at SDCC and attended the Korra panel (and sent us information about it via twitter in real-time) posted a video that she recorded of the martial arts demo that was shown at the panel.

The video shows Sifu Kisu performing traditional Chinese martial arts; Mac Danzig and Jeremy Umphries performing mixed martial arts; and Steve Terada and Jake Huang performing martial arts "tricking". These performances are used as video references by the animators when they are working on animating the fight scenes in the show.